3:2 Pulldown

The method used to telecinefilms to NTSCvideo. Film runs at 24 fps, but NTSC video runs a 30 fps (or 60 interlaced fields per second). To get these to numbers compatible, film frames are captured for 2 and 3 video fields alternating.

Film: 1 2 3 4 5 6 7 8
Video: 11222334445566677888

It means that NTSC DVDs run at the same speed as the original film, but it sometimes introduces an unpleasant jerking in slow panning shots.

NTSCvideo actually runs at a frame rate of 29.97 frames per second. Therefore, during telecine (and, hence, to make 3:2 Pulldown actually work), the film passing through the telecine machine is slowed to a frame rate of 23.976 frames per second.

This causes a problem: to get a precise matchback to your negative after cutting a film project on video (i.e., in a digitalnon-linear editing system), you must edit at 24fps. Otherwise, your negative cutter has to sync up your video cut and the film negative in a lockbox and check the edits by eye...and they're gonna be slightly off.

Therefore, when digitizing telecined footage (if you want to cut at 24fps...not necessary for video-only release), the video must be sped up by 1%. Digital NLEs have a 'pulldown' function which provides this solution.